1. Field of the Invention
The present invention relates to a digital camera system (e.g., SLR digital camera system) including a camera body and an interchangeable lens that is detachably attached to the camera body, and in particular the present invention relates to a diaphragm driving device of the digital camera system which is capable of recording moving images while controlling the operation of an adjustable diaphragm of the interchangeable lens.
2. Description of the Prior Art
In conventional camera systems using an interchangeable photographic lens (hereinafter referred to as an interchangeable lens), especially in SLR digital camera systems, the aperture size of a diaphragm of the interchangeable lens is controlled by a diaphragm-driving slide plate provided in a camera body. Namely, the interchangeable lens includes a diaphragm control bar for changing the F-number via rotation thereof about an optical axis, and the camera body includes the diaphragm slide plate which engages with the diaphragm control bar when the interchangeable lens is attached to the camera body. When taking a still image (i.e., a still photograph), before a shutter of the camera is released, the diaphragm-driving slide plate is moved in advance to a position in accordance with the brightness of an object image so that the diaphragm control bar rotates about the optical axis via engagement of the diaphragm-driving slide plate therewith.
Conventionally, when taking a still image (still photograph) upon a shutter release, the diaphragm-driving slide plate is moved by an amount of movement (distance) that is determined in accordance with the brightness of an object image by a linear moving device having a latch mechanism. Accordingly, the conventional diaphragm driving device of the SLR digital camera cannot be applied to the capturing of moving images (movies), because upon taking the moving images the brightness of an object image is continuously changed, while the diaphragm value of the interchangeable lens cannot be changed by the conventional linear moving device having the latch mechanism.